package com.jason.interceptor;

import com.fasterxml.jackson.databind.ObjectMapper;
import com.jason.utlis.JWTUtils;
import com.jason.utlis.JsonData;
import io.jsonwebtoken.Claims;
import org.apache.commons.lang3.StringUtils;
import org.springframework.web.servlet.HandlerInterceptor;
import org.springframework.web.servlet.ModelAndView;

import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import java.io.PrintWriter;

public class LoginInterceptor implements HandlerInterceptor {

    /**
     * 进入到controller之前的方法
     * @param request
     * @param response
     * @param handler
     * @return
     * @throws Exception
     */
    @Override
    public boolean preHandle(HttpServletRequest request, HttpServletResponse response, Object handler) throws Exception {
        try{
        String accesToken = request.getHeader("token");
        if (accesToken==null){
            accesToken=request.getParameter("token");
        }
        if (StringUtils.isNotBlank(accesToken)) {
            Claims claims = JWTUtils.checkJWT(accesToken);
            if (claims == null) {
                //告诉登录失败，重新登录
                sendJsonMessage(response, JsonData.bulidError("登录过期，重新登录"));
                return false;
            }
            Integer id = (Integer) claims.get("id");
            String name = (String) claims.get("name");
            request.setAttribute("user_id", id);
            request.setAttribute("name", name);

            return true;
            }
        }catch (Exception e){
//            e.printStackTrace();
            //登录失败
        }
        sendJsonMessage(response, JsonData.bulidError("登录过期，重新登录"));

        return false;
    }

    /**
     * 相应json数据给前端
     * @param response
     * @param obj
     */
    public static void sendJsonMessage(HttpServletResponse response,Object obj){
        try {
            ObjectMapper objectMapper=new ObjectMapper();
            response.setContentType("application/json; charset=utf-8");
            PrintWriter writer = response.getWriter();
            writer.print(objectMapper.writeValueAsString(obj));
            writer.close();
            response.flushBuffer();

        }catch (Exception e){
            e.printStackTrace();
        }
    }

    @Override
    public void postHandle(HttpServletRequest request, HttpServletResponse response, Object handler, ModelAndView modelAndView) throws Exception {

    }

    @Override
    public void afterCompletion(HttpServletRequest request, HttpServletResponse response, Object handler, Exception ex) throws Exception {

    }
}
